The wheels are widely used fixtures, for examples, vehicle or skating shoes use wheels for easy movement. However, the conventional wheel for vehicle such as bicycle comprises a hub at the center of wheel and a plurality of spokes extending radially form the hub. The spokes sweep quickly when the wheel is rotated. This could be dangerous for children when they carelessly insert their finger into the rotating wheel and get hurt by the sweeping spokes.
It is the object of the present invention to provides an activating device having an activating element moved axially, by the centrifugal force provided by the rotating wheel, to electrically connect two conductive plates such that alarming sound and lighting are generated for warning. Therefore, the children can be alarmed that the wheel is rotating and be prevented from harm.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: